The need for increased functionality of display controllers—preferably at lower prices—drives product evolution in ever-shorter cycles. Over the years it has been shown that an increase in display controller functionality requires an even faster increase in internal bus bandwidth. Initial hardware designs used ‘point to point’ connectivity. The advent of IT hardware caused proprietary bus structures to appear. Standardization of the IT market generated a fast evolution of cheap standard bus designs. High-end requirements were fulfilled with proprietary busses, often driving future standards forward.
First generations of multi-head display controllers focused on the display of graphics data. Standard bus based system could handle this well. The emerging demand for showing video and/or RGB images and related and/or embedded metadata was handled by either limiting the data rate caused by video data transfer on a standard bus (leading to lower quality) or by using additional proprietary busses. The need for higher numbers of higher quality video/RGB images and more powerful video and metadata processing grew stronger and caused the design of highly complex bus solutions (most of the time still based upon existing standards).
A similar evolution was noted in IT networking. Low-speed networking evolved very rapidly over the years towards very high-speed networking—10 Gbit/sec data rate being readily available, 1 Gbit/sec already becoming standard for high-end workstations and laptops, 100 Mbit/sec almost being outdated. Switch and router bus capacities were driven by the ever-faster network speed and QoS requirements—nowadays guaranteeing sufficient processing and transfer capacity to avoid packet loss. At the same time there has been an evolution in compression technology—MPEG, MPEG2, MPEG4, JPEG, JPGEG2000 . . . —to yield higher compression rate for the same visible quality of images.
Today, more and more customers demand solutions where the distribution is done of multiple sources in different locations, with sources being of multiple signal types, to different places where display units 1 such as projectors, plasma displays, monitors are available. Today this can be solved with presently available display controllers 2 (such as e.g. Hydra or Argus, available from the applicant for the present patent). The classical system architecture, however, has the disadvantage that one display controller 2, e.g. a Hydra multi-viewer display controller, drives one display unit 1 (which may consist of multiple screens). One can easily come to a stage where one such display controller 2 is not big enough to drive a display unit 1 or where multiple display controllers in different locations are required to display the same sources. In this case, an external distribution device 3, such as a router or matrix switch, e.g. CVBS/SDI/RGB routers, is required to enable the switching and multiplexing of input signals to several destinations, as illustrated in FIG. 1. This architecture has the disadvantage that every display controller 2 needs to be connected to the external distribution device 3, e.g. router, by as many cables as there are images to be displayed on a single display unit 1 (screen). Cabling therefore is a major issue. It is furthermore a disadvantage of such implementation that the external video/audio distribution in the central external distribution device 3, required to bring the input source signals to the relevant display controllers 2 is a high cost (amplifiers, matrix switchers, cabling, . . . ). Another disadvantage, as already indicated, is the fact that the distribution internally in the display controller requires ever more complex bus solutions.
In the particular case of a control room, e.g. a broadcast studio, utilities control room or an air traffic control tower operations room, such control room is equipped with a multitude of displays, in the latter case allowing one or more air traffic controllers to monitor the air and ground traffic, landings and all vehicle movements on the runway and the apron. Most of today's systems used in a traffic control environment are based on the principle of “one monitor for one application”, in a static configuration. Every display has its proper mouse and keyboard, and is thus dedicated to one particular application or system. Consequently, the human machine interface is composed of several displays, of different sizes and shapes, with each its own user interface. This situation is sub-optimum from an ergonomic perspective. Existing solutions using KVM switches fall short in providing the required functionality when operators demand simultaneous viewing and interoperability with applications running on multiple application servers.
There is room for improvement in multi-head display controllers and multi-head displays.